OAK drying time.

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

clemsonfor

Minister of Fire
Dec 15, 2011
2,513
Greenwood county, SC
I am posting this as an illustration of real world results. I wont argue that the 3 year oak rule and that some of you will never burn oak before 3 years, but.

I have some oak that I got from a logger that was cut on a job about this time last year, I cut it and split it over a few weeks. IT was cut green and was soaking wet when I split it. The tree I took a sample piece from was about 40+ inches in diameter. I pulled one split off the top( if I remember I will pull off more and resplit tomorrow) and resplit it. Took moisture readings and they were either 23 or 24% in about 4 different places about equal. This stuff should be ready this burning season after our summer. It has about 1 year right now and I have a good 6 months before I would even think about using it, I think its easily in range to loose another 5% by next winter???

Will let you know the results of more splits when I do them. This was I think from a red oak, I had red and white but just did not pay close attention when I picked the piece and from where.
 
If you took it off the top of the stack, it might be drier that splits that are farther down. But I'd say the stack might lose 5% over the summer if it's single-row in the wind...
 
  • Like
Reactions: OldLumberKid
3 years for oak?

Not me... I got a half cord of dripping wet white oak last spring and its 28% humidity on the meter now. I expect it to cook out to 18-20% by fall.
 
  • Like
Reactions: OldLumberKid
Each location & weather conditions effect drying times.
Here, birch is dry enough to burn after 1 year.
2 year birch is real good wood.
3 year birch is awesome .
aging is important too. ;)
 
I am just starting to track the drying of a split of red oak. I oven-dried a small sample to determine initial moisture content, so now I can measure the split's MC by weighing it and doing a little math. I've been doing the same with some mulberry and elm. It was amazing how fast the oak split dropped moisture initially. Measured within a couple of hours of when the tree came down, it was at 79%. One week later it was at 60%. It can't keep that sort of pace, of course, or it would be burnable after 3 weeks, not 3 years. It may be that oak drops a lot of moisture very fast early in the drying process, but slows dramatically so that those last few percent, which make the difference between okay and great, are lost very, very slowly.
 
It may be that oak drops a lot of moisture very fast early in the drying process, but slows dramatically so that those last few percent, which make the difference between okay and great, are lost very, very slowly.

I'm not a scientist and I don't play one on T.V. and I didn't stay at a Holiday Inn Express last night, but I believe the drying time of oak, as well as other woods, is tied to the density of the wood and the average moisture content of each type of wood.

Because oak is a very dense wood with a medium to high moisture content, depending on type, it takes longer for the moisture to escape from deep within the splits. Moisture close to the surface will leave the wood quicker because of a greater surface area and less "travel distance" which may be the reason for such a drastic change over a short time in your readings. Locust, on the other hand, is much more dense than oak but generally dries quicker because it has a very low moisture content to begin with.

Other variables come into play when drying wood such as the conditions in which the tree grew, how much sun and wind the stacks are getting and the like. Of course I could just be all wet myself!:p

So at this point you what I'm gonna say: THE BEST WAY TO MEASURE THE MOISTURE CONTENT OF FIREWOOD IS WITH A MULTI-YEAR CALLANDER! ;)
 
I have oak that I burn in two years with no problems. Stuff I split last year is now at 23% on a fresh split and will be ready for next winter
 
I have oak that I burn in two years with no problems. Stuff I split last year is now at 23% on a fresh split and will be ready for next winter
This is exactly what i have seen.



And yes the split was on the top, i was not going to dig down to midway in the 4ft tall pile just for a jeewiz type thing that just popped in my head as i passed the pile.

The split was not huge either but was not really thin. It was a wedge shape, maybe 5"s x 3"s? I know some say its smaller but really i made some splits large for this season and i did not like them. They seem to burn almost as fast in my cat stove as smaller splits drafted down, a bit longer but not hugely noticeable. And the biggest thing is getting them to fit in the stove, its hard to navigate the huge splits in teh door and then find splits to go on top of those when there larger, so this last year i tried to vary my splits more. Mostly medium say 50% and then 25% small and 25% big. Now do i really have those percentage of splits, doubt it but i would like too!!!
 
  • Like
Reactions: OldLumberKid
Forgot to add, oak i checked was smaller splits
 
I stacked two cords of oak in a great drying spot in my yard where its gets sun all day and its on a high spot so it gets the full effect of any wind. After two years it was down to 19-21%, splits were smaller than I usually like but I wanted to try and burn it after two years, it ended up where the cord in the front that got most of the sun was driest and the back row bottom layers were a little less dry, 23-25%, I ended up burning the one cord and saved the back row cord for next year. It depends on many factors but its doabale in two years.
 
slows dramatically so that those last few percent, which make the difference between okay and great, are lost very, very slowly.
Right. I like it down there, approaching 16%, so that's gonna take a while. I've got some dead standing Red that I stacked last summer in double rows, was in the upper 20s to start. I'll be interested to see how it is doing this fall.
 
I stacked two cords of oak in a great drying spot in my yard where its gets sun all day and its on a high spot so it gets the full effect of any wind. After two years it was down to 19-21%, splits were smaller than I usually like but I wanted to try and burn it after two years, it ended up where the cord in the front that got most of the sun was driest and the back row bottom layers were a little less dry, 23-25%, I ended up burning the one cord and saved the back row cord for next year. It depends on many factors but its doabale in two years.

Good point, Im sure the back row on mine might be different
 
Right. I like it down there, approaching 16%, so that's gonna take a while. I've got some dead standing Red that I stacked last summer in double rows, was in the upper 20s to start. I'll be interested to see how it is doing this fall.
I dont think below 15% or really 16% is possible in my climate. I have some red oak that i have stacked in my shed i just cant bring myself to burn, for some reason. I sometimes take a split off the top to make some oak kindleing but stopped that this year. Its about a face cord. Its stacked along the back of my open shed and serves as a half back wall to it. It is going on 4 years i think and has been sitting at 15% give or take a few points for over 18 months now. I checked it this year for giggles and it was right around 16% and i checked last year same tiem adn it was the same reading then as well. It will vary depending upon the temp like yall say but its not moved as far as MC in over a year or almost 2 i bet.

Just giving this example for what its worth. That means it was in the 16% range or so after 2 years and has been there since.
 
  • Like
Reactions: Bster13
so thats 23% for 1 year split and after 3.5ish years split and stacked the whole time, the last almost 3 years under a shed, similar red oak only measures 15%.
 
It will vary depending upon the temp like yall say but its not moved as far as MC in over a year or almost 2 i bet.

Actually it varies with relative humidity, rather than temperature. An equilibrium moisture content of 16% lines up with average RH around 80%, give or take a few points.
 
I know RH effects it, but on here i read folks talking about MM reading different at differnt temps. Say if you could get 80% RH at both 20F and 90F your MM will read different at both temps. No proof just repeating what i read here.
 
your MM will read different at both temps.

Yes, but that's because electronic moisture meters are just specialized ohm meters; they measure electrical resistance, and the electrical resistance of wood varies with temperature even as the actual moisture content is stable.
 
  • Like
Reactions: OldLumberKid
You should be able to get wood to 12% in any US lower 48 climate. If I can get wood down to 12% here in the wet and soggy PNW, as others can in Maine, anyone can anywhere. It may take a while though. No need for a calendar or guessing though. A $12 moisture meter will do a great job, and in my case, my wood is a lot dryer than I thought it was. I do not know why there are so many 'rules' to drying wood debated on this forum, but it seems silly to me. Split an average size piece of wood from the center of the pile, poke it with a tester, and whallah... the average moisture in the wood stack. Simple, instant, cheap, no BS, no guessing, no argument.

And yes, most moisture meters are calibrated to read Doug Fir at 68-70 degrees. The variation between species of firewood is not that large (few percent at most, unless you happen to be burning something like Phillipines mahogany). If your MM did not come with correction tables, you can get charts for adjusting the reading for different species and temps. Temperature and species are the variables used for correction (not humidity). Species variable are rather small when considering that you are reading to burn firewood. Temp variation is not that great either but the meter will read low in colder weather, and high in warmer weather. These things are made for woodworking, flooring and kiln drying where small variations makes a huge difference. With firewood? It should not really matter. A 1% moisture difference at 20% overall will lead to about a 1% difference in heat from your wood. Pretty small spuds there.

You can read/download species and temperature pin type MM correction tables here: http://www.delmhorst.com/Product-Support/Correction-Tables
 
Well this thread is promising. My OAK will be almost 2yrs old by the Fall of 2014 as a newbie. I hope the moisture content levels off by then and additional drying time provides a minimal benefit.
 
I've had good results with 2 year seasoned oak - I'd eventually like to get to where I'm burning 3-4 year seasoned oak but not there yet. Moisture still comes out of the end of most pieces when I throw it in the fire, but usually not for long.
 
Well this thread is promising. My OAK will be almost 2yrs old by the Fall of 2014 as a newbie. I hope the moisture content levels off by then and additional drying time provides a minimal benefit.
If that stack is getting good wind, not a lot of rows jammed together, and the splits aren't real big, it should be burnable if not perfect. Like StihlHead said, most US locations the EMC is 12-13%, but I've found that 16% burns really well.
 
Short of the wood sizzling--which happened to me one year--how can you tell there is moisture coming out of the ends.

look at the end of the splits, you will actually the water. I'm know theres a pic of it somewhere on here just not sure where
 
Status
Not open for further replies.